Digital time-resolved optical measurement of discharge currents in long air gaps.

Shortcomings in the dynamic range and the frequency bandwidth of current diagnostic methods mean that measurement of the time-resolved discharge current in a long air gap discharge is still a serious problem. This work presents data from a novel discharge current sensor that takes the parameters required to determine the accuracy of the current measurement into account. The design of a coaxial current sensor with ±0.7% accuracy and a bandwidth of 75 MHz is presented. A digital optical fiber transmission system with a bandwidth that exceeds 100 MHz is used to transmit the signal. To demonstrate the efficiency of the whole system, experiments using a rod-plane discharge geometry with 2 m and 4 m air gap lengths are performed to analyze the measured current data in comparison with that taken from synchronized high-speed photographs. The results demonstrate that the investigated experimental set-up improves substantially the understanding of the fundamental mechanisms of long air gap discharges.

On-line estimation of laser-drilled hole depth using a machine vision method.

The paper presents a novel method for monitoring and estimating the depth of a laser-drilled hole using machine vision. Through on-line image acquisition and analysis in laser machining processes, we could simultaneously obtain correlations between the machining processes and analyzed images. Based on the machine vision method, the depths of laser-machined holes could be estimated in real time. Therefore, a low cost on-line inspection system is developed to increase productivity. All of the processing work was performed in air under standard atmospheric conditions and gas assist was used. A correlation between the cumulative size of the laser-induced plasma region and the depth of the hole is presented. The result indicates that the estimated depths of the laser-drilled holes were a linear function of the cumulative plasma size, with a high degree of confidence. This research provides a novel machine vision-based method for estimating the depths of laser-drilled holes in real time.

[Development of a nitric oxide supply system for respiratory distress treatments].

College of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan,430074 Inhaled nitric oxide (INO) is increasingly being used in medical treatments of high blood pressure, acute respiratory distress syndrome (ARDS) and some diseases related with lungs. In this paper, in view of the problems in the current supply systems of NO for the treatments of respiratory failure, an INO system for clinical applications is designed based on experimental studies. Its continuous trial run shows that the outlet concentration of NO can be supplied constantly, and the ratio of NO2/NO is about 2.7%. So it satisfies the clinical requirements (NO2/NO<5%). In comparison of the conventional NO supply systems, this system has significant advantages, it can work so long as the air and the electricity exist.